Furnace moving system

ABSTRACT

A system for moving 40-ton melting furnaces from the furnace pit to the rebuilding shop and return. A furnace with base and superstructure, with a plurality of air bearings in the base for moving the furnace on an air film to a pit platform, with a first lifting unit for raising and lowering the platform and furnace, and a second lifting unit for raising the furnace from the platform for inserting and removing air bearings.

1451 Feb. 12, 1974 United States Patent 91 Baker et al.

3,419,164 12/1968 ONeill............................ 180/125 X FOREIGN PATENTS OR APPLICATIONS FURNACE MOVING SYSTEM [75] Inventors: Terry M. Baker; Robert B. Kieding;

Henry W. Huthsing; Robert E.

1,214,813 l2/l970 Great Britain...................... 2l4/l H Burdlck, all of Santa Barbara, Calif.

Assignee: Rolair Systems, Inc., Santa Barbara,

Primary ExaminerFrank E. Werner Attorney, Agent, or Firm-Harris, Kern, Wallen & Tinsley Calif.

22 Filed: Jan. 2, 1973 Appl. No.: 320,141

[-5 7] ABSTRACT A system for moving 40-ton melting furnaces from the furnace pit to the rebuilding shop and return. A furus. 214/1 'R, 180/125, 214/1 BE,

nace with base and superstructure, with a plurality of air bearings in the base for moving the furnace on an 51 int.

air film to a pit platform, with a first lifting unit for raising and lowering the platform and furnace, and a second lifting unit for raising the. furnace from the platform for inserting and removing air bearings.

[58] Field of Search....;.....

References Cited UNITED STATES PATENTS 5/1965 Coates..............;........... 214/1 D X 3 Claims, 5 Drawing Figures 111111; IIIIIIIII II PAIENIEB FEB 1 21974 RISE 1 FURNACE MOVING SYSTEM This invention relates to large melting furnaces such as are used in the production of aluminum, glass and the like, which may handle melts in the order of 40-tons and higher and weigh in excess of 250,000 pounds. More particularly, the invention is related to a system for moving such furnaces between the operating location in a furnace pit and a rebuilding location in a remotely located shop area.

A typical melting furnace includes a steel cage or framework and a lining of refractory brick and appropriate auxiliary equipment. The large furnaces have an operating life in the order of three-years, after which it is necessary to remove the brick, rework or rebuild the frame and auxiliary equipment, and then rebuild the inner structure with new refractory brick. This is accomplished at the present time by taking the furnace out of production, permitting it to cool in position in the production line, and removing the refractory material at the location on the production line. The framework'or cage may then be partially disassembled and transported to the shop area. After reworking, the frame and equipment are transported back to the production site and assembled. The new brick work is installed,therefractory material is cured, and the furnace is ready to resume production.

The rebuilding operation usually requires several weeks and as a result, the production site is out of operation for this length of time. With the present invention, the lost production time is reduced to a few days. The present invention provides for removing an entire furnace from the production site, transporting it to a shop where it can be rebuilt, and immediately moving a stand-by furnace into place at the production site.

This can be accomplished in a relatively short time as 7 compared to the time required to disassemble, repair and rebuild a furnace on the site.

The present invention provides for moving the completed furnace on a plurality of air bearings between the shop and the furnace pit. A platform is provided in the pit for receiving the furnace with the platform being movable vertically to raise the furnace from the pit bottom to the floor level. Another lifting mechanism is provided for raising the furnace from the platform for inserting and removing the air bearings.

The air bearings themselves are conventional and typical replaceable air bearings are shown in the copending application of Robert E. Burdick Replaceable Air Cushion Device, Ser. No. 180,666 filed Sept. 15, I971.

In operation, compressed air is delivered toan air bearing to inflate the bearing and raise the load, and to generate a film of air between the bearing and the ground surface, resulting in a very low friction between the load and the ground.

Other objects, advantages, features and results will more fully appear in the course of the following description. The drawing merely shows, and the description merely describes a preferred embodiment of the present invention which is used in the way of illustration or example.

In the drawing:

FIG. 1 is a perspective view of a production site showing a furnace being moved to a pit;

FIG. 2 is a view similar to that of FIG. 1 showing the furnace being moved into position on the platform of the pit; and

FIGS. 3, 4 and 5 are views taken along the line 3 of FIG. 2, showing three steps in the lowering of the furnace into the pit.

In FIG. 1, a typical large melting furnace 10 is being moved along a roadway ill from a rebuilding shop to a pit 12 at the production site. Similar furnaces l3 and 14 are in position and in use at similar pit locations. The furnace 10 may be conventional in design with a base and a steel frame superstructure 21 with a refractory brick lining 22. A door 23 with appropriate door opening mechanism is provided at one end. Various auxiliary equipment required for the operation of the furnace may be attached thereto and are not identified separately in the drawing.

The furnace base 20 includes receptacles indicated generally at 25 for slidingly receiving air bearings 26. In the embodiment illustrated four air bearings are provided at each side, but of course any number of air bearings may be used depending upon the load and the rating of the individual bearings. The air bearings may be installed and removed in the conventional manner as illustrated in the aforementioned copending application Ser. No. 180,666. In an alternative configuration, the bearings may be mounted in a transporter or platform, with the entire transporter being inserted and removed at the furnace base.

The furnace base includes means for distributing air to each of the air bearings from an air supply line which is connected to any suitable source of air under pressure. When the air supply is connected to the bearings, the bearings are inflated, raising the furnace from the ground surface, and floating the furnace of a film of air between the bearings and the ground surface. When in this condition, the large load has low friction and is readily moved along the roadway 11, typically by tractors 31 connected to the furnace by frame units 32 at the front and rear. A -ton capacity furnace will weigh 250,000 pounds and will have substantial inertia, and a pair of tractors provide the necessary forces for starting and stopping movement and for guiding the furnace during movement.

The furnace pit 40 is set in the ground at the production site, typically in a concrete foundation 41. A platform 42 is positioned in the pit and a lifting system, typically a set of hydraulic jacks 43, is mounted in the bottom of the pit for raising and lowering the platform 42. The platform is shown in the raised position in FIGS. 14, and in the lowered position in FIG. 5, with the platform resting on the base of the pit so that the pit floor carries the weight of the loaded furnace during production.

A second lifting system is provided for raising and lowering the furnace with respect to the platform and typically may comprise another set of hydraulic jacks 45 mounted in the bottom of the pit, with the upper ends of the jacks 45 moving through openings in the platform 42 for directly engaging the furnace base.

In operation, the platform 42 is raised to the upper position flush with the roadway 11 by the jacks 43. The furnace 10 is floated into position on the platform 42, as illustrated in FIG. 2. The air supply to the air bearings may be turned off. The jacks 45 are then raised, moving through the platfrom 42 and engaging the furnace base to raise the furnace above the platfrom, as

illustrated in FIG. 3. The air bearings may then be removed, after which the jacks 45 are actuated to lower the furnace onto the platform, as illustrated in FIG. 4. The jacks 43 are then actuated to lower the platform and furnace to the bottom of the pit, as illustrated in FIG. 5. The furnace is now ready for connection and production.

At a later time when rebuilding of the furnace is desired, the procedure is reversed and the furnace is removed to the shop area, after which another stand-by furnace is installed as previously described and is ready for production. Production time lost is due only to the time required for removing one furnace and installing another. This may be a matter of a few days, in contrast to the several weeks presently required to rebuild a furnace on the site.

The jacks 43 and 45 may be permanently installed in the pit or alternatively, may be removable so that one set of jacks 43 and one set of jacks 45 may be used in conjunction with several production locations.

The brick. work in a furnace is highly susceptible to cracking, particularly at the mortar joints, when the structure is subjected to stress. Movement of such a large unit on wheels or skids or similar moving devices produces the undesirable furnace stresses as a result of 2 5 roadway bumps and shocks. The present furnace moving system with the load floating on an air film from a plurality of diaphragms provides air cushioning of the road shock and substantially eliminates the risk of cracked joints in the rebuilt furnace.

I claim:

1. In a system for moving large melting furnaces and the like into and out of a pit, the furnace having a base and a superstructure, the combination of:

a plurality of air bearings carried in said base;

a furnace platform positioned in said pit and engagable with said base for supporting said furnace; first lifting means for raising and lowering said platform in said pit;

second lifting means for raising and lowering said furnace from said platform; and

distribution means in said furnace base for directing air under pressure to each of said air bearings for raising said furnace base from said platform when said air bearings are inflated floating said furnace on an air film.

2. A system as defined in claim 1 wherein said first lifting means and said second lifting means are mounted in said pit, with said second lifting means engagable with said furnace base through said platform,

3. A system as defined in claim 2 wherein said furnace base includes receptacle means for slidingly receiving said air bearings, permitting removal and insertion of air bearings when said furnace is raised from said platform by said second lifting means. 

1. In a system for moving large melting furnaces and the like into and out of a pit, the furnace having a base and a superstructure, the combination of: a plurality of air bearings carried in said base; a furnace platform positioned in said pit and engagable with said base for supporting said furnace; first lifting means for raising and lowering said platform in said pit; second lifting means for raising and lowering said furnace from said platform; and distribution means in said furnace base for directing air under pressure to each of said air bearings for raising said furnace base from said platform when said air bearings are inflated floating said furnace on an air film.
 2. A system as defined in claim 1 wherein said first lifting means and said second lifting means are mounted in said pit, with said second lifting means engagable with said furnace base through said platform.
 3. A system as defined in claim 2 wherein said furnace base includes receptacle means for slidingly receiving said air bearings, permitting removal and insertion of air bearings when said furnace is raised from said platform by said second lifting means. 